Field of the Invention
The present invention relates to a stereoscopic video recording method, a stereoscopic video recording medium, a stereoscopic video reproducing method, a stereoscopic video recording apparatus, and a stereoscopic video reproducing apparatus.
Description of the Background Art
With the progress of encoding techniques for compressing digital video signals, it has become possible to implement optical disk apparatuses with excellent searchability and operability by recording compressed video signals to optical disks. Such optical disk apparatuses are free from degradation caused by dubbing, because they record digital video signals instead of analog video signals, and such optical disk apparatuses offer improved reliability because they employ non-contact optical recording and reproduction.
Encoding methods for compressing such digital video signals include the MPEG (Moving Picture coding Experts Group) standards, for example. The MPEG compression offers improved compression efficiency as compared with “intra” compression methods such as motion JPEG, but it still has restrictions due to the use of motion-compensated prediction in the temporal direction; for example, searches can be made only in units of groups of multiple pictures (GOPs), and access on the disk requires accessing an intra-compressed I picture first. Accordingly, Japanese Patent Application Laid-Open No. 2005-260988 (Patent Document 1) suggests a devised data format on an optical disk.
However, the data format of Patent Document 1 has been made only for filing of two-dimensional, flat images. For filing of stereoscopic images, the method of Japanese Patent Application Laid-Open No. 2007-166651 has to be adopted, in which a right-eye image and a left-eye image are separately displayed in the first and second fields of a TV signal, and the two individual field images are viewed by the respective eyes through the use of means such as polarizing eyeglasses.
Viewing stereoscopic (hereinafter referred to also as 3D) video for many hours causes discomforts such as eye fatigue and 3D motion sickness, because the viewer moves the eyes in the focal direction with increased frequency. Three-dimensional viewing will be problematic especially when the point of attention busily moves in the depth direction. Also, in particular, the display of subtitles and the like requires continuously switching the eye focus, and may cause more intense discomforts like eye fatigue and 3D motion sickness than the viewing of ordinary 3D video.
Also, as to the recording of stereoscopic video information, when filing a stereoscopic video that employs parallax between right-eye images and left-eye images on an optical disk, it was not possible to handle a video stream including a mixture of flat (hereinafter referred to also as 2D) images and stereoscopic (3D) images. Particularly, for example, when the display apparatus is switched while the reproducing apparatus is reproducing stereoscopic video, or when a display apparatus is newly connected, information required for 3D display cannot be sent to the display apparatus side in a linked manner, and so the settings in the display apparatus cannot be changed instantaneously.
Also, as to the recording of stereoscopic video information, when filing a stereoscopic video employing parallax between right-eye and left-eye images on an optical disk, there is no video control information that allows recording of broadcasted stereoscopic video and that enables settings in the display apparatus and the reproducing apparatus.
Also, distributed content, such as movies, are usually released at different times, for preferentially releasing businesses such as movie theaters and for the distribution as media, and therefore “code” is provided to limit the region where the movie can be viewed, according to the conditions of distribution of the movie. Also, the distribution of stereoscopic video content is affected by the extent of proliferation of compatible display apparatuses, and it is necessary to further set separate regional restrictions for 3D video and for 2D video. However, conventional systems do not meet such requirements.
Also, it was not possible to superimpose information about the content, copyright information, 3D display scheme information, OSD information, multi-angle information, etc. on a stereoscopic video stream, and therefore it was not possible to instantaneously change the settings on the display apparatus side, not on the reproducing apparatus side.
Also, unlike ordinary 2D video information, 3D video information utilizing parallax includes information for the left-eye and information for the right eye, and the amount of information is doubled and filing efficiency is deteriorated.
Also, while increased eye fatigue occurs during the reproduction of 3D video with an increased degree of three-dimensionality, it was not possible to give a warning to the user in advance, according to the degree of three-dimensionality, or to restrict the viewing according to the age of the user. Also, while increased eye fatigue occurs during the reproduction of 3D video with an increased degree of three-dimensionality, it was not possible to alleviate the three-dimensionality of the content on the reproducing apparatus side.